The present invention is directed generally to optical communications systems, devices, and methods. More particularly, the invention relates to systems, devices, and methods for processing signals in optical communications systems, and the design and upgrade of nodes and network elements in optical communications systems.
Optical communications systems are typically formed from nodes and network elements connected by optical communications paths, such as optical fiber. The nodes and network elements perform functions such as adding, dropping, switching, and amplifying optical signals so that they reach their intended destination in the network.
There are several different types network architectures in use today, including point to point networks, all-optical networks, ring networks, mesh networks, and others. In addition, there are different protection schemes in use to protect traffic from failures in the network. However, as traffic volumes increase and more services are offered, older networks can no longer efficiently carry traffic and do not offer the flexibility needed in a modern communications system. Unfortunately, upgrading such networks often requires that traffic across the network be interrupted, which is costly to network operators and inconvenient to customers. Some solutions have been proposed to provide for more flexibility in optical networks, such as U.S. Pat. No. 5,557,439, but those solutions are often inadequate for modern optical communications systems.
In view of these difficulties, there is a clear need for improved networks, network nodes and elements, and methods, that provide for better network flexibility.